D题:Regular Bridge 乱搞. 构造 这题乱搞一下即可了.构造一个有桥并且每一个点的度数都为k的无向图. 方法非常多.也不好叙述.. 代码例如以下: #include <cstdio> #include <cstring> #include <cmath> #include <queue> #include <stack> #include <map> #include <algorithm> #define…

题目传送门 /* 数学/暴力:只要一个数的最后三位能被8整除,那么它就是答案:用到sprintf把数字转移成字符读入 */ #include <cstdio> #include <algorithm> #include <cstring> #include <iostream> #include <cmath> #include <vector> using namespace std; ; const int INF = 0x3f3…

题目传送门 /* DFS: 排序后一个一个出发往后找,找到>r为止,比赛写了return : */ #include <cstdio> #include <iostream> #include <cstring> #include <cmath> #include <algorithm> #include <vector> #include <map> #include <queue> #include…

题目传送门 /* 水题:遍历一边先找AB,再BA,再遍历一边先找BA,再AB,两种情况满足一种就YES */ #include <cstdio> #include <iostream> #include <cstring> #include <cmath> #include <algorithm> #include <vector> #include <map> #include <queue> #includ…

E. Brackets in Implications Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/550/problem/E Description Implication is a function of two logical arguments, its value is false if and only if the value of the first argument is…

D. Regular Bridge Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/550/problem/D Description An undirected graph is called k-regular, if the degrees of all its vertices are equal k. An edge of a connected graph is called a b…

C. Divisibility by Eight Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/550/problem/C Description You are given a non-negative integer n, its decimal representation consists of at most 100 digits and doesn't contain leadin…

B. Preparing Olympiad Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/550/problem/B Description You have n problems. You have estimated the difficulty of the i-th one as integer ci. Now you want to prepare a problemset for…

A. Two Substrings Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/550/problem/A Description You are given string s. Your task is to determine if the given string s contains two non-overlapping substrings "AB" and "…

链接:http://codeforces.com/contest/550/problem/A 这是我第一次玩cf这种比赛,前面做了几场练习,觉得div2的前面几个还是比较水的. 所以看到这道题我果断觉得是拼手速的题啊,结果瞬间就一发WA,连pretest都没通过, 然后开始想,发现没那么简单的样子,很多坑的样子,当我写了2个循环把AB BA 都扫一遍时, 认为考虑周全后,觉得能过了,就交,过了pretest,当时看room里面 大多数还没过A呢,觉得很高兴. 然后学长说这题能叉很多人,我不懂什么…